Tribute to Urborg [Dominaria United]

Set: Dominaria United Type: Instant Rarity: Common Cost: {1}{B} Kicker {1}{U} (You may pay an additional {1}{U} as you cast this spell.) Target creature gets -2/-2 until end of turn. If this spell was kicked, that creature gets an additional -1/-1 each turn for each instant and sorcery card in your graveyard.